In general, a groove portion, and a land portion sectioned by the groove portion are provided in a tread surface of a pneumatic tire, and various tread patterns are formed in the tread surface in correspondence to demanded tire performance and used condition. Conventionally, there has been known a pneumatic tire in which a wall surface of a land portion is formed by a zigzag surface, for the purpose of improving a handling performance (a snow handling performance) on an iced road surface, and the like. For example, in the following Patent Document 1, there is disclosed a tire in which a wall surface of a circumferential rib provided in the vicinity of a tire equator is formed by a zigzag surface.
However, in the pneumatic tire mentioned above, a rigidity of the relevant portion is lowered by forming the wall surface of the land portion by the zigzag surface, and there is a problem that a handling performance (a dry handling performance) on a dry road surface is deteriorated. The pneumatic tire described in the following Patent Document 1 is structured such as to improve the snow handling performance, however, does not suggest any means for securing the dry handling performance at all.    Patent Document 1: Japanese Unexamined Patent Publication No. 11-245631